2018, Vicedo-Cabrera, Ana Maria, Guo, Yuming, Sera, Francesco, Huber, Veronika, Schleussner, Carl-Friedrich, Mitchell, Dann, Tong, Shilu, de Sousa Zanotti Stagliorio Coelho, Micheline, Saldiva, Paulo Hilario Nascimento, Lavigne, Eric, Matus Correa, Patricia, Valdes Ortega, Nicolas, Kan, Haidong, Osorio, Samuel, Kyselý, Jan, Urban, Aleš, Jaakkola, Jouni J. K., Ryti, Niilo R. I., Pascal, Mathilde, Goodman, Patrick G., Zeka, Ariana, Michelozzi, Paola, Scortichini, Matteo, Hashizume, Masahiro, Honda, Yasushi, Hurtado-Diaz, Magali, Cruz, Julio, Seposo, Xerxes, Kim, Ho, Tobias, Aurelio, Íñiguez, Carmen, Forsberg, Bertil, Åström, Daniel Oudin, Ragettli, Martina S., Röösli, Martin, Guo, Yue Leon, Wu, Chang-fu, Zanobetti, Antonella, Schwartz, Joel, Bell, Michelle L., Dang, Tran Ngoc, Do Van, Dung, Heaviside, Clare, Vardoulakis, Sotiris, Hajat, Shakoor, Haines, Andy, Armstrong, Ben, Ebi, Kristie L., Gasparrini, Antonio

The Paris Agreement binds all nations to undertake ambitious efforts to combat climate change, with the commitment to “hold warming well below 2 °C in global mean temperature (GMT), relative to pre-industrial levels, and to pursue efforts to limit warming to 1.5 °C”. The 1.5 °C limit constitutes an ambitious goal for which greater evidence on its benefits for health would help guide policy and potentially increase the motivation for action. Here we contribute to this gap with an assessment on the potential health benefits, in terms of reductions in temperature-related mortality, derived from the compliance to the agreed temperature targets, compared to more extreme warming scenarios. We performed a multi-region analysis in 451 locations in 23 countries with different climate zones, and evaluated changes in heat and cold-related mortality under scenarios consistent with the Paris Agreement targets (1.5 and 2 °C) and more extreme GMT increases (3 and 4 °C), and under the assumption of no changes in demographic distribution and vulnerability. Our results suggest that limiting warming below 2 °C could prevent large increases in temperature-related mortality in most regions worldwide. The comparison between 1.5 and 2 °C is more complex and characterized by higher uncertainty, with geographical differences that indicate potential benefits limited to areas located in warmer climates, where direct climate change impacts will be more discernible.

2021, Rockström, Johan, Gupta, Joyeeta, Lenton, Timothy M., Qin, Dahe, Lade, Steven J., Abrams, Jesse F., Jacobson, Lisa, Rocha, Juan C., Zimm, Caroline, Bai, Xuemei, Bala, Govindasamy, Bringezu, Stefan, Broadgate, Wendy, Bunn, Stuart E., DeClerck, Fabrice, Ebi, Kristie L., Gong, Peng, Gordon, Chris, Kanie, Norichika, Liverman, Diana M., Nakicenovic, Nebojsa, Obura, David, Ramanathan, Veerabhadran, Verburg, Peter H., van Vuuren, Detlef P., Winkelmann, Ricarda

Keeping the Earth system in a stable and resilient state, to safeguard Earth's life support systems while ensuring that Earth's benefits, risks, and related responsibilities are equitably shared, constitutes the grand challenge for human development in the Anthropocene. Here, we describe a framework that the recently formed Earth Commission will use to define and quantify target ranges for a “safe and just corridor” that meets these goals. Although “safe” and “just” Earth system targets are interrelated, we see safe as primarily referring to a stable Earth system and just targets as being associated with meeting human needs and reducing exposure to risks. To align safe and just dimensions, we propose to address the equity dimensions of each safe target for Earth system regulating systems and processes. The more stringent of the safe or just target ranges then defines the corridor. Identifying levers of social transformation aimed at meeting the safe and just targets and challenges associated with translating the corridor to actors at multiple scales present scope for future work.